Process for making a



[benzimidazyl- (2) l-ethane or a Patented Nov. 15 1949 PROCESS FORMAKING ozIfi-DI- [BENZIMID AZYL- (2) I ETI-IYLENES Jules Meyer, Basel,.Charles Graenacher, Riehen, and Franz Ackermann, Binningen, Sw tzerland,assignors to Cilia Limited, Basel, Switzerland,

a Swiss firm N Drawing. Applicatii i'n November 21, 1945, Se-

rial No. 630,118. In Switzerland December 21,

8 Claims. (Cl. 260-240) 1 According to thi inventionwfi-di-[benzimidazy1-(2) l-ethylenes are made by treatingccZfl-disubstitution product thereof or salt of either of thesecompounds at a raised temperature with a dyhydrogenating agent.

Among the substitution products of aifi-di- Ibenzimidazyl-(Z)l-ethanecoming into considtaining as substituents in the benzene nucleus halogenatoms or nitro or methoxy group, such as on; ,B-di-[6-chlorobenzimidazyl(2)1 ethane, or :p-di- [G-nitrobenzimidazyl: (2),] -ethane or (1113-di-[6-methoxy-benzimidazyl (2) ethane; and alsoaIfi-dl-[bfil'lZlmidaZYl-(Z)143111941188 containing sulpho groups assubstituents in the benzene nucleus. There also come into considerationasymmetrically substituted aIfi-di- [benzimidazyl- (2) l-ethanes.

As salts of the mp-di-[benzimidazyl-(Z) l-ethanes there may bementioned, for example, the hydrochlorides or sulphates.

The azp-di-[benzimidazyl-(ml-ethanes mentioned above may be designatedas di-benzimidazoles in which the two fL-CQJbOIl atoms of the imidazolenuclei are connected with one another through a -CH2CH2- bridge.Furthermore, the parent materials mentioned above may also be designatedas members selected from the group consisting of an imidazole'of theformula sented by the formula N N Z/ CCH2CHzC \I wherein m is a ring ofthe benzene series in which two vicinal carbon atoms are bound to thenitrogen atoms of the i midazole nuclei, and R is a member selected fromthe group consisting of hydrogen, alkyl and aralkyl.

As dehydrogenating agents there come into consideration, for example,mild oxidizing agents. Examples of such agent are: Compounds of divalentmercury, such as mercuric acetate or mercuric oxide; potassiumpermanganate or pyrolusitej copper oxide or copper sulphate; hydrogenperoxide; selenium dioxide; platinum oxide; and more especiallywater-soluble ferric salts, such as ferric sulphate, ferric chloride orpotassium ferricyanide; and finally organic compounds having anoxidizing action, such as nitro-compounds, for example, nitrobenzene.

' The elements selenium and sulphur constitute a further group ofdehydrogenating agents.

Lastly, there'may also be mentioned as dehydrogenating agentsdehydrogenation catalysts, for example, finely subdivided metals of theiron group, such as finely divided nickel, or cobalt, furthermorecopper, platinum or palladium, used 'as such or supported on a carrier.

Especially effective dehydrogenating agents are mild oxidizing agents,that is oxidizing agents which do not destroy thedi-benzimidazyl-ethylenes by further oxidation, and furthermore finelysubdivided metals of the iron'group. The preferred dehydrcgenatingagents are, however, mild oxidizing agents. These agents, especiallyferric salts and mercuric salts, are characterized by a good yield ofdehydrogenation product.

The most suitable dehydrogenating agents are, however, mild oxidizingagents such as ferric sulphate.

The treatment with the dehydrogenating agent is carried out at a raisedtemperature, preferably at a temperature exceeding C. but lower than thedecomposition temperature of the parent material, for example, at -2500., advantageously in the presence of a solvent for theaifi-di-[bellzimidazyl-(2) l-ethane compound, for example, with theaddition of glacial acetic acid, a dilute mineral acid or water (whenthe starting materials contain sulphonic acid roups). Thus, for example,mercuric acetate, which is soluble in glacial acetic acid, can becausedto act upon a solution of one of the substituted ethanes mentionedabove in glacial acetic acid, for example, at '100150 C. Ferricsulphate, which has proved to be an especially advantageousdehydrogenatir'ig'agent, can advantageously be caused to act at atemperature exceeding C., for ex ating agent, the reaction can bebrought about by heating at 250300 C. with the exclusion of air, andmolten 2-methyl-benz imida 1e,.foreigample, may be used as a solvent.

The alkylation or aralkylation of the aZfl-di- [benzimidazyl-(2)l-ethanes, which may be carried out if desired, may be brought about inthe usual manner, for example, by treatment with an alkyl halide praralkylha'lide'; such as benzyl chloride, advantageouslywith' theaddition of an acid-binding agent. For the alkylation there 'may also beused dialkyl sulphates, such as dimethyl sulphate 7 The products of theinventionwhen in a dissolved or finely dispersed; condition:- exhibit amore or less pronounced fluorescence, and' also.

have a more or less marked afiinity for cellulose fibers. By virtue ofthese propertiesthe products can be used for improving, for example;for. the optical bleaching of' materials, especially cellulose fibres.

Among the aZfi-di- [benzimidazyl- (2) l-ethanes to be used as startingmaterials zfl-di- [benzimidazyl-(2) l-ethane is known, and indeed twoprocesses for making this compound have been described. In accordanceWith one known process brtho-phenylene diamine is heated with succinicacid, whereby a crude product expressly referred to as being black isobtained. This baking process, apart from the fact that it yields aprod,- uct of dark color, is also unsuitable for use on a Copendingapplication Serial No. 515,024, filed December 20, 1943,.now Patent No.2,463,264, discloses' that materials, particularly textile materials,can be improved by bringing onto these materials-sat, any; desired stageof their manufacturing or, improving process compounds of "the generalformula" commercial scale, because it leads to a final prod- I uct(which as is known melts at over 310 C.) in a solid form which makes itdifficult to remove the product from the reaction vessel. In the secondknown process succinic acid and orthophenylene diamine are heated" for 7hours in the presence of 4Nhydrochloric acid, and the yield amounts toonly 28 per cent of. the calculated yield. On account. of the poor yieldthis process is also precluded from commercial use.

Ithas now been found that salts of a:fi-di- [benzimidazyl-(Z)l-ethaneor. of its substitution products are obtained ingood yield by heating asuitable ortho-phenylene diamine with succinic acid or a functionalderivative thereof. in the presence of a mineral acid containing wateruntil the content of the dibenzimidazyl compound no longer increases,and, if desired, .causing an alkylating or aralkylating agent to actonthe dig-d1.- [benzimidazyl-(2) l-ethane so obtained.

'As suitable" ortho-phenylene diamines to be used as starting materialsthere are tobe under-.-

7 stood those in which one amino group is. primary and the other aminogroup is. primary or secondary. Such ortho-phenylene diaminesvare, forexample, ortho-phenylene diamine itself, 1-methyl-3 :4-diaminobenzene,1-isopropyl-3z4- diaminobenzene, 1-methoXy-3:4-diaminobenzene,1-chloro-3 4-diamino-benzene and. l -nitro- 3:4-diaminobenzene.

As functional derivatives of .succinic acid. there come intoconsideration, for example, the anhydride or an ester thereof.

The reaction of the ortho-phenylenediamines of the kind describedabovewith succinicvacid. or a functional derivative thereof is conductedat a raised temperature, for example, at 100-140 0., in the presence ofa mineral acid containing water, for example, with the addition ofsulphuric acid of' 40-50 per cent strength, or of hydro: chloric acid of20 per cent strength or-stronger, and, 'if necessary, under pressure.The; heating is continued until the content ofthe di-benzimidazylcompound formed no longer 7 increases, which will generally be the caseafterv heating for a period of 24-72 hours. 7

A C-R I tl. wherein Astands for an aromatic nucleus-which, if desired,;may be substituted R1 stands for hydrogenora: substitnent, for example;a. benzyl radical or a hydroxyalkyl radicahand Rstands for arr alkylradical unsaturatedin mp-position,

Example 1' A solution of 23.4,. parts-of;mp di-[benziemidazy1-.(2)]-ethane of. the formula in parts of glacialacetic acid-ismixed with a solution of 61.2 parts of mercuric acetate-in 240 parts ofglacial acetic acid, and the mixture is-heated, while stirring-for 3hours at the boil in a refluxing apparatus; The acetic acid is thencompletely removedby distillation under reduced pressure. The dryyellow-brown residue inter-y mingled with some metallic mercury isextracted by boiling with hydrochloric acid-of 10per cent; strengthuntilall the azfl-di-[benzimidazyl-(2) ethylene has been extracted. Thehydrochloric acid extracts arekunited, and hydrogen sulphide isintroduced into the combined extracts while heating, in order to removetraces of dissolved mercury in the form of sulphide. The hot filtrate ismixed with ammonia to give a weakly alkaline reaction, and precipitatethe pale yellowish colored a113-di- [benzimidazyl- (2) l-ethylene of theformula I The product so obtained in then separated by filtering withsuction, washed until neutral, and

yield.

talline powder.

., dried at 100 C. .It is a feebly yellowish colored powder. The yieldamounts to 21 parts.

Instead of mercuric acetate, another mercuric salt such as mercuricpropionate may be used. The aforesaid uzfi di [benzimidazyl (2) ethaneused as starting material is advantageously prepared in the followingmanner:

64.8 parts of ortho-phenylene diamine and 36 parts of succinic acid areadded with the exclusion of air to 240 parts of sulphuric acid of 50 percent. strength. The whole is heated for 48-72 hours in a refluxapparatus at 105-l10 C. then diluted with water, allowed to cool to l020C. and advantageously allowed to stand for -20 hours. The0:2]3-di-[b61'lZiII1idi1ZY1-(2) l-ethane sulphate, which separates, isremoved by filtration, washed with a little water, and dried.

The yield is over 90 per cent. of the theoretical uzp-Di-lbenzimidazyl(2)] ethane sulphate'forms a colorless crystalline powder, which issoluble in acidified water. The base may be separated from the solutionby means of an alkali, for example, ammonia.

Example 2 1.8 parts of a: 8-di-[N-benzyl-benzimidazyl- (2) l-ethane(obtainable in the usual manner by the treatment ofmfi-di-[benzimidazyl-(Z) ethane with benzyl chloride) are dissolved inparts of glacial acetic acid, and then mixed with a solution of 2.8parts of mercuric acetate in 15 parts of glacial acetic acid. The clearsolution is heated for 3 hours at PLO-145 C., and after a short timefine gold-yellow needles precipitate. After the 3 hours the solution hasbecome clear again and metallic mercury collected at the bottom. Thesupernatant clear solution is carefully poured oil, and the glacialacetic acid is removed therefrom by distillation under reduced pressure.The gold-yellow colored residue is digested with a dilute aqueoussolution of ammonia, and then filtered. The filter residue is washeduntil neutral, and dried at 100 C.

By recrystallisation from alcohol ocZfi-di- [N- benzyl-benzimidazyl-(Z)l-ethylene of the formula is obtained in the form of a pale yellow finecrys- Example 3 A solution of 3.5 parts of a:/3-di[6-nitrobenz'imidazyl-(Z) -ethane in 50 parts of glacial acetic acid ismixed with a solution of 6.8 parts of mercuric acetate in 30 parts ofglacial acetic acid. The clear solution is heated for 3 hours at 135-140 C. and in a short time a yellow colored precipitate is formed. Iheglacial acetic acid is then distilled under reduced pressure, and theresidue is extracted by boiling for a short time in 75 parts of alcoholand 16 parts of a caustic soda solution of 10 per cent. strength, themercury remaining undissolved. The whole is filtered, and the alcohol isremoved by distillation. The residue is taken up in water, thesuspension is neutralized with a mineral acid, and filtered. The filterresidue is well washed with water, and then dried at 100 C.

The affl-di [6-nitrobenzimidazy1-(2) l-ethyl- .ene of the formula soobtained is a strongly yellow colored powder.

In a similar manner mB-di-[G-methoxy-benzimidazyl-(Z) l-ethane may bedehydrogenated.

The aforesaid aZfi-di-[G-Ilitl'O-benZiIIlidfiZYl- (2)1-ethane used asStarting material may be prepared in the following manner:

33 parts of 1-nitro-3: l-diaminobenzene are stirred with 500 parts ofsulphuric acid of 40 per cent. strength. 12 parts of succinic acid areadded, and the whole is gently boiled for about 24 hours in a refluxapparatus. The whole is then diluted with water and allowed to cool. Thecondensation product which separates is removed by filtration, washedwith water, and dissolved in a hot dilute solution of caustic soda,whereupon the sodium salt separates in the form of yellow needles. Thelatter are isolated by filtration, washed with a solution of sodiumchloride, dissolved in a dilute caustic soda solution, precipitated withacetic acid, filtered, washed with water, and dried.

The resulting a e-di- [G-nitro-benzimidazyl- (ZN-ethane is a palecolored powder. It dissolves in a dilute caustic soda solution with ayellow coloration, and gives a colorless solution in glacial aceticacid.

The azfl-di-[d-methoxy benzimidazyl-(2) ethane, which is also mentionedabove as a starting material, can be obtained in a manner similar tothat described in Example 7, below for preparing a :p-di-[fi-methyl-benzimidazyl- 2) lethane.

Example 4 3.3 parts of ocZfi-di- [6-chlorobenzimidazyl-(2) ethane aredissolved in 25 parts of glacial acetic acid and 6.8 parts of mercuricacetate are dissolved in 30 parts of glacial acetic acid. The unitedsolutions are then'heated 'for 3 hours at 135-140 0., and in a shorttime an orange-red precipitate is formed. The glacial acetic acid isthen distilled under reduced pressure. The greyyellow residue isextracted by boiling with a large quantity of hydrochloric acid of 10per cent. strength, whereby the sparingly soluble dihydrochloride of thedehydrogenation product is formed. The whole is filtered hot and allowedto cool, whereuponthe dihydrochloride precipitates in the form of brightyellow crystals, which are then separated by filtration. In order toproduce the free base the filter residue is dissolved in hot alcoholwith the addition of a concentrated solution of ammonia, and the clearsolution is stirred into a large excess of Water, whereupon the paleyellow base flocculates. The whole is filtered, and the filter residueis washed with water until neutral, and dried at C.

The aZfi-dl-[6-chIO1'0bBnZlmld5tZY1-(2) -ethylene of the formula it tthus purified is apale yellow powder.

amaze! Aim-a (quite ssimilarnznanner Am- [benzimidazyl- (2) -,3-fi-chlorobenzimidazyl- G29 ethane can be dehydrogenated.

The a! fi di- 6-chlorobenzimidazyl-"(2),] -ethane used abovesas startingmaterial can be sob-tainecl in .a similanman-ner to that described inlExa-mple 7 below for preparing mfi-di- [fi-methyl benzimidazyl- (2-)l-ethane.

The oz- [benzimidazyl- (2) 1 3 -[6 -chlorobenzimidazyl ('2=) -eth'anealso "mentioned above as a starting material can beobtained in thefollowing-nranner: 7

-1-9*parts of ;8- Ebenzimidazyl- (2) l -propion'-ic acid and M parts-of-1-chloro-'3 z'4- diaminobenzene "are boiled in a refiux'apparatus with200 partspfthydrOchlotie acid -of '1'5 -per *cent. strength for 48"hours, an'd 'then allowed to cool.

f lheiprocedureis thesa-me' as -that describediin Example 7' below forpreparing a 13- di- [ii-methylbenzimi'dazyl-Q'F]-ethane. *There" is thus'ob tamed a-' Ebenzimidazyl- (2)1 5- [fi-ch-lorobenzi midazyl (2)"1-ethane in-the -'''form of a colorless powder, which is soluble-indilute-hydrochloric acidor-As'ulphurie acid.

' I l-Emample 5 solution of F 8 parts of azB-di-[fi-isopropylbenzimidazyl- 2) l-ethane dihydrochlor-ide in '50 :partszofglacial acetic-acid is mixed with-a solution of 14 parts of mercuricacetate in GO-parts of =glacial acetic acid. "-The clear solution isheated, -wh-ile stirring, for '3' hoursat -1135-1450 0., whereupon sa:yellow crystalline precipitate for-Ins in a short time.

The glacial acetic acid is-then-distilled -under 're'clucedrpressure.The 'blaek-yellowresidue is extracted? by boiling with 2'5 parts ofalcoho'l' and 7.=1.par.ts of a caustic soda solutionof per cent.strength, Whereupon the whole is dissolved with the exception-:ofthemercury. The m'ixtureis 40 filtered, the alcohol is removed fromthefiltrate by distillation, the residue" is taken up in Water,neutralized with sulphuric acid ;of .lOrper ;cent. strength, andfiltered. washed, and-driedzat-lOOaC. :In this mannerazeadialfi-isopropylbenzimida- -zyl- ('2'). l-ethy-lene'zof theformula gExample 6 "l80'partsr'of aqs-di [ben'zimidazyl-JZ) l=ethane sulphate areheated "in an autoclave, -while,stirring, "with parts of Water,405;,partao.:cryst.alline ferric chloride (FeClsBHzO) and '50 parts ofconcentrated,sulphuric acid for 3 hours at 200- 205 C.

After zcooling, the reaction mixtureiis triiturated with 4500 parts ofwater and allowed to/stand for 1-2 hours. The finely pulverized reactionproduct is then separated by filtering with suction, and

The rfilter residue jiis 45 produces' a 'liluelcoloration w lthpotassium terrocyanide; l he crudeproduct?so obtainedsisa=paileyellowolive powder, which consi'sts mainly -'-of= the sul- "phateof the dehydrogenation product-produced.

*I-n order to obtaih the free base thecrudeproduct is-extracted by"boiling w'ith -a mixture-of 900 -parts of a oa-ustic so'da *solution ofI4 percent. strength and 4000 *parts of alcohol for l hour, thedehydrogenation *product passing "into solution. "The'e0ole'd solutionis -filtered"-to "remove -solid constituents, the filter residue *is"washed with alcohol -containi-ng sodium hydroxide, and the -=alcoholicfiltrate "is --evaporated to dryness. "The residue is taken upin water,the suspension neutralizedwith-mineral'racid andfiltered. The a :p-d-i-Ebenz-in-iida'zyl (2 ethylene so obtained --is=a pale"beige coloredpowder,- solu'tionsof which "in alcohol exhibit a strong bluefluorescence :in =ultra-violet'fili'glit;

llmmzzlej 2.7 parts of cup-di-[6-methyl-benzimidazyl- (2)1-ethane areheated ninaan autoclave, while stirrin with 20 parts of water, 8.1 partsof .icrystalline-f-erric chloride (FeClxIGHzQ') and 1135 parts ofconcentrated sulphuric acid for j3"hours at '200=2'05 C.

After cooling, the reaction mixture 1 is ,dige'sted with "about 60'parts' of ;,water,' the reaction product which separates is. isolated by.cfiltration, and washed with wateruntil a "test pprtiomprolducefi -noblue "coloration with potassium ,iferrocyanide. Thecrude'product soobtained canlbe recrystallized from alcohol rendered Weakly. alkaline:with ammonia. azp 'Di [fimethylebenzimidazyl-l2)i,l ethylene oftheformula is obtained in good yield in the form of a-crystalline feeblypale; yellow colored product. 7

In a quite analogous-mannerN:N'-dimethyloz p-di- [benzimidazyl- (2)-ethane canbe dehydrogenated.

The a ,8-di-, L6 +methyl:-'benzim-idazyl- (2) -ethane mentioned above asstarting material may be,preparedinthesfollowingimanner 24.4 parts ofl-methy1-3 :4-diaminobenzeneiand 12.4 parts of succinimacideare boiledin a reflux apparatus with 200 parts of hydrochloric acid of -15 per-cent; strength for 4'8 hours. The whole is allowed to-:coc)l,--"thecrystals-which separate are isolated byfiltrat-ion,-'and, ifuiecessary,there-'- mainder-of the-product is recovered from the filr' trate by'theaddition "of'sodium-chloride or concentrated -sulphuricacid. Theisolated product is then washedwith asolution of sodium'chloride,and-dried. I

' The aradi l6=methy1=benzimidazyh(2) ]-.ethane' hydrochloride "soobtaine'd is 'a colorless ,crystallinegpowder. It can befurtherpurifled'from dilute' hydrochloric*acfd. FFrom'the hydrochloricacid solution the base-'cambe precipitated in the formotacolorlesspowderby means of an alkali, for-example,- sodium'earbonate.

washed with watercuntil testirpontiomnozlonger ethane also mentionedabove as a starting mate- Example 8 3.5 parts ofone-di-[6-nitrobenzimidazyl-(2)lethane are heated with 30 parts ofwater, 8.1 parts of crystalline ferric chloride (FeClsfiHzO) and 3 partsof concentrated sulphuric acid in a closed vessel, while stirring, for 3hours at 135- 140" C.

After cooling, the reaction mixture is filtered with suction and thegreenish yellow filter residue is washed with water until a test portionno longer produces a blue coloration with potassium ferrocyanide.

The dried filter residue is purified by rapidly extracting it by boilingwith a mixture of 95 parts of alcohol and 12 parts of a caustic sodasolution of 10 per cent. strength and removing the undissolved materialby filtration. The filtrate is then neutralized with a mineral acid, thealcohol is removed by distillation, the residue is taken up in a littlewater, and filtered. The filter residue is washed with water and dried.

The aLZB-di- [finitrobenzimidazyl- (2) l-ethylene so obtained is astrongly yellow colored powder.

Example 9 10 parts of mB-di-[benzimidazyl-(Z)l-ethane are dissolved in amelt of 100 parts of Z-methylbenzimidazole, and the mixture is thenmixed with 10 parts of a nickel catalyst with the exclusion of air andgradually heated to 260300 C. A lively evolution of hydrogen occurs. Assoon as this evolution has ceased the melt is allowed to cool, and thenboiled with alcohol to dissolve the 2-methyl-benzimidazo1e. The residueis then extracted by boiling with 250 parts of alcohol and 20 parts of acaustic soda solution of 10 per cent. strength. The imidazole productpasses into solution, and is freed from nickel by filtration. By pouringthe filtrate into water and neutralizing the alkali with sulphuric acid,the crude cat di- [benzimidazyl- (2) l-ethylene is precipitated, and thelatter is washed with water and then dried. By redissolution in alcoholwith the addition of a little sodium hydroxide and recrystallizationfrom alcoholic hydrochloric acid, the new compound is purified andobtained in the'form of a pale yellowish colored crystalline powder.

Example 20 parts of azfi-di-ibenzimidazyl-(2)l-ethane 10 V evaporated todryness. 9.2 parts of the'sodium' a ,6- di- [benzimidazyl- (2) l-ethanedisulphonate of the formula so obtained are dissolved in 500 parts ofwater, and rendered weakly alkaline with 40 parts of a N solution ofcaustic soda. 18 parts of p0 tassium ferricyanide are then added, andthe so: lution is heated at the boil for 12 hours in a refiux apparatus.

After cooling, a small quantity of a brown pre- 540 parts ofazfl-di-[benzimidazyl-(z) l-ethane sulphate are heated in an autoclave,while stirring, with 1741 parts of an aqueous ferric sulphate solutionof 52 per cent. strength. 150 parts of water and 152 parts of pureconcentrated sulphuric acid for 4-5 hours at 210-215 C.

After cooling, the reaction mixture is vigor-v ously stirred with 5000parts of water, and allowed to stand for a few hours. The finelypulverulent reaction product is separated by filtering with suction, andwashed with water (about 70,000 parts) until a test portion no longerproduces a blue coloration with potassium ferrocyanide.

The crude product so obtained is a pale yellow powder, which consistsmainlyof the sulphate of the dehydrogenation product formed.

For the purpose of purification the crude prodnot is boiled at leastonce with a mixture of 1200 parts of /2N sulphuric acid and 1200 partsof water in a reflux apparatus for 20 minutes. After cooling thesolution, the resulting magma is filtered with suction and washed withwater until a test portion no longer produces a blue coloration withpotassium ferrocyanide.

In order to obtain the free base the still moist paste (the filterresidue) is stirred for a few hours with 1200 parts of water and 480parts of a concentrated solution of ammonia. magna is then filtered withsuction, washed until the washing water has a neutral reaction, and thefilter residue dried at 130 C.

The utp-di-[benzimidazyl-(2)l-ethylene so obtained is a faintlyyellowish colored powder,

solutions of which in alcohol exhibit a strong blue fluorescence inultra-violet light.

one Di-[6-methyl-benzimidazyl-(2)l-ethane of the formula H O CH:

The aqueous suspension The alkaline 1 ageagaet- N-sub'stituti'onr.products '4 thereof r. containing at least one Nj-falkylradicalgsubstitution products thereof containing an alkyl group in-atleastonee-u benzenering, substitution. products thereofncon-r taining ahalogen atomin at least one benzene ring, and salts; of these compounds,with-lanloxidizingagentselected from thefgroup consistingrOi temperatureranging from 100.250.. C.

2.".'Piocess..for .the. manufacture of an vaura-(lin-[b'nzirhidazyl-(Zil -,ethylene, which. comprises heating a memberselected from the group con-e. sistingof animidazoleof-v the formula,-

N -substitutiom xproductsi thereof containing at 1938171201181iNj-alkylziradical, substitution products thereof containing-ran alkyl"group in atleast one i benzene ering; substitution products thereofc'ontaining a haldgenzatom in: at leas-t one-benzene ring; andzsaltsmfithese' compounds, with a watersolublecferriosalt at atemperature ranging from i 100?-:250I'Ca3 3;: Process: for; .the.manufacture of an at/3 C11 [benzimidazylsQY-l ethyle'ne, whichcomprisesheatingza.zmember;=selected from the group: consistingof :anfimidazoleof the-formula o' om om o N-substitution i :productsn: thereof:containingtrat leastfione.cN-alkyl radical, substitution products?-thereof; containing-an: alkyl;grouprinicat;- least one benzene fring-substitution products thereof: con-1 ring,;.and ;:-salts':2of:,these1compounds"; with ferric sulphate/in the,-'presence:2of ea zminerala'acid 1 con taining JQWQtBIUat as temperature ranging from I, 150-;220:'C.

4;;- Process eforcthemnanufacture'. 'of: an: a ,8'-Tdi'-[benzimida'zyl:-:(2):]ethylene; which comprises: heating amembrts'elehted: from i the igroup-consisting 20f: ani midazolerofrithesformula:

306v) V I 12% tainingea chalflgenratom .in ,at :least. one.. v benzenering land rsalts {oft thesescompounds, .with av mer: cu-ricQsalt-of a.ltemperature ranging from 100m 25QL'Cia 5.t Pr.ocessifolt-,themanufacture of. an-Olfi 'd'i.-L

[benzimidazyL-Q)Ll-zethylene, T which 7 comprises; L

heating: a. Jnemberrselectedt from the, group one, sisting ,-,of-:animidazoleot the .formula l substitution"products thereof containing atleast one- N-alkyl' radi'ca1,'-'substitution --products"' thereofcontaining ;an= alkyl group in"'at'--leastone benzene ring;-substitution products thereof conmtaining-a halogen atom in" atleast onebenzene water-soluble ferrlcsalts and lmercurlcnsaltsatfa:

ring, and salts of these compounds, with mercuric acetate'inthe presence'of acetic acid at a tem-t perature ranging 'frbm'-100-150C.

' chlorobenzimida'zyl -(2) l-ethylene of the formula with;mercuric-sacetateain the presencx-aeof acetic. acidtto atemperatureranging from 1004-50920;

7. PIOCeSSefOlJthemanufaoture'oha sulphate pfetheflrzzfi-di-[benzimidazyl-KZX] -,eth-ylene of them-:- formulaa whichcomprises-heating V, a sulphate :of the *oc edi-IDDZimidaZYIj-(ZlJ.ethaneof the formula '55s; taining a halogen atomzirt'at,leastsiionesbenzene with ferric sulphateeinapresence of dilute sulphuricacid to a temperature ranging from 150- 220310. "w

enerofr theaformula' H; Hmv

75;-1which-comprises zheating a sulphate'mf: ctheeu 25+ 7 14di-[G-methyl-benzimidazyl-(2) J-ethane Of the REFERENCES CITED formulaThe following references are of record in the N file of this patent:

5 Richter, Textbook of Organic Chemistry, John Wiley 8; Sons, New York,N. Y., 1938, page H,c- 653.

l Shriner et aL, J. Am. Chem. 800., 63, pages 2277 L I H and 2278(August 1941). with ferric sulphate in presence of dilute sul- 10Brumngs et Chem pages 337 phuric acid to a temperature ranging from 150-and 342 (March 1944)- 220 C.

J ULES MEYER. CHARLES GRAENACHER. FRANZ ACKERMANN. 15

